Methods and compositions for recovery of lithium from liquid solutions with nanoparticles

ABSTRACT

The present disclosure relates, according to some embodiments, to a method for recovery of lithium ions from a lithium-ion containing liquid, the method comprising the steps of coating a nanoparticle with a styrene monomer; polymerizing the styrene monomer to form a poly-styrene-coated nanoparticle; attaching a dibenzo-12-crown-4-ether to the polystyrene-coated nanoparticle to form a lithium adsorbing medium; exposing the lithium ion-containing liquid to the lithium adsorbing medium to form a lithium-rich adsorbing medium; and extracting the lithium ion from the lithium-rich adsorbing medium.

BACKGROUND

The present disclosure relates, in some embodiments, to isolatinglithium from aqueous sources.

Lithium and lithium salts have many uses that range frompharmaceuticals, ceramics, metallurgy, pyrotechnics, and militaryapplications. The recent surge in renewable energy efforts has created alarge demand for lithium to make rechargeable lithium ion batteries suchas those for portable electronics and electric cars.

Most of the world's lithium is obtained by extracting brine water fromunderground pools, placing the brine water into ponds, and then lettingthe heat from the sun evaporate the ponds to leave the salt behind. Thismethod is the most widely used today because the mining of lithium oresis much more expensive and is not economical. While solar evaporation isless expensive than direct mining of lithium ores, the product derivedfrom solar evaporation is not pure and requires additional processing toseparate the lithium salts from other salts found in the brine.

It would be desirable to selectively recover lithium salts from brinewater in a stable form and with high purity.

BRIEF SUMMARY

According to an aspect, a method includes the steps of coating ananoparticle with a styrene monomer; polymerizing the styrene monomer toform a polystyrene-coated nanoparticle; and attaching a crown ether tothe polystyrene-coated nanoparticle to form a lithium adsorbing medium.The method may include exposing the lithium ion-containing liquid to thelithium adsorbing medium to form a lithium-rich adsorbing medium and alithium-depleted liquid; and extracting the lithium ion from thelithium-rich adsorbing medium to form an extracted lithium ion and arecycled lithium-adsorbing medium.

According to an aspect, a lithium adsorbing medium for recoveringlithium ions from a lithium-ion containing liquid includes apolystyrene-coated nanoparticle; and a crown ether, the lithiumadsorbing medium prepared by a process including the steps of: coating ananoparticle with a styrene monomer; polymerizing the styrene monomer toform the polystyrene-coated nanoparticle; attaching the crown ether tothe polystyrene-coated nanoparticle to form a lithium adsorbing medium;exposing the lithium ion-containing liquid to the lithium adsorbingmedium to form a lithium-rich adsorbing medium and a lithium-depletedliquid; and extracting the lithium ion from the lithium-rich adsorbingmedium to form an extracted lithium ion and a recycled lithium-adsorbingmedium.

In an example, the nanoparticles have a surface area from about 10square meters per gram to about 5,000 square meters per gram.Nanoparticles may include a surface area from about 10 square meters pergram to about 500 square meters per gram. Nanoparticles may include aferrous material such as magnetic iron. The nanoparticles may include anon-magnetic iron. Nanoparticles may include iron, ferrous iron, andiron oxide. A crown ether may include dibenzo-12-crown-4-ether,diaza-12-crown-4 ether, dibenzo-15-crown-5 ether, diaza-15-crown-5ether, dibenzo-18-crown-6 ether, and diaza-18-crown-6 ether.

According to an aspect, a method includes separating an extractedlithium ion from a recycled lithium-adsorbing medium. In someembodiments, a lithium-rich adsorbing medium is magnetically separatedfrom a lithium-depleted liquid. Extracting the lithium ion from thelithium-rich adsorbing medium may be performed by treating thelithium-rich adsorbing medium with a weak acid. The weak acid mayinclude one or more of carbonic acid, acetic acid, phosphoric acid,hydrofluoric acid, oxalic acid, and combinations thereof.

According to an aspect, a method includes drying the precipitatedlithium salt to form a dried lithium salt, and separating a lithium-richadsorbing medium from lithium-depleted liquid by centrifugation. In someembodiments, the method includes separating the lithium-rich adsorbingmedium from the lithium-depleted liquid by centrifugation. Polymerizingmay provide for a preferred attachment site for a crown ether bylimiting interference with the crown ether oxygens and the nanoparticlefor the adsorption of the lithium ion. Polymerizing allows thenanoparticle to be used in an acidic condition and for the removal ofthe lithium ion from the lithium-rich adsorbing medium without or withlimited degrading of the nanoparticle. Extracting may include exposingthe lithium-rich adsorbing medium to a water containing a carbondioxide. The extracted lithium ion may be precipitated to form aprecipitated lithium salt, in which the precipitated lithium salt mayinclude lithium carbonate, lithium silicate, lithium oxalate, andcombinations thereof. Coating may include adding the nanoparticle to asolution containing the styrene monomer and a free radical initiator.

In some embodiments, a method for creating a lithium adsorbing medium,includes the steps of coating a nanoparticle with a styrene monomer;polymerizing the styrene monomer to form a polystyrene-coatednanoparticle; and attaching a dibenzo-12-crown-4-ether to thepolystyrene-coated nanoparticle to form the lithium adsorbing medium.

According to some embodiments, a lithium adsorbing medium for recoveringlithium ions from a lithium-ion containing liquid is provided. Thelithium adsorbing medium may include a nanoparticle including an iron; apolystyrene coating a surface of the nanoparticle; and a crown etherattached to the polystyrene. The iron may include a magnetic iron, anon-magnetic iron, and combinations thereof. The crown ether may includedibenzo-12-crown-4-ether, diaza-12-crown-4 ether, dibenzo-15-crown-5ether, diaza-15-crown-5 ether, dibenzo-18-crown-6 ether, anddiaza-18-crown-6 ether. In some embodiments, greater than about 75% ofthe surface of the nanoparticle is coated with polystyrene. According tosome embodiments, greater than about 95% of the surface of thenanoparticle is coated with the polystyrene.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the disclosure may be understood by referring, inpart, to the present disclosure and the accompanying drawings, in which:

FIG. 1 illustrates a flow chart of a method for recovering lithium ionsfrom a lithium ion containing liquid according to a specific exampleembodiment of the disclosure.

DETAILED DESCRIPTION

The present disclosure relates, in some embodiments, to methods andcompositions for recovery of lithium from liquid solutions withnanoparticles. The liquid solutions may be naturally occurring brinesources. The methods and compositions may selectively extract lithiumsalts from brine solutions. Brine solutions include those obtained fromseawater, saline lakes, shallow groundwater bines associated with salineor dry lakes, geothermal brines, and deep brines from sedimentarybasins. For example, brine may come from Death Valley, California andfrom Argentina. Selectively extracting lithium salts may have theadvantage over existing extraction methods of not requiring furtherisolation from other salts such as sodium and potassium salts.Additionally, the described nanoparticles may be recycled to reducewaste and cost of production of the nanoparticles. In some embodiments,magnetic nanoparticles may desirably permit magnetic separation of thenanoparticles from the brine once the lithium has been sequestered fromthe brine. Magnetic separation of the nanoparticles from the fluid isadvantageous over traditional filtering methods since it can be used ina high throughput manner without requiring filters that get clogged upand must be replaced. A magnetic particle may include a ferrous materialwhether or not the ferrous material is in a magnetic state. The ferrousparticle may be extracted by exposure to a magnetic field. The ferrousparticle in a magnetic state may be extracted by exposure to anotherferrous material and/or a magnetic field.

FIG. 1 illustrates a flow chart of a method for recovering lithium ionsfrom a lithium ion containing liquid. As shown in FIG. 1, a method 100includes combining 102 a nanoparticle, a styrene monomer, and a radicalinitiator. These elements can be combined in a glass or metal containerand can be mixed with an overhead stirrer, a magnetic stir bar, shaken,and combinations thereof. Combining 102 can be performed in an aqueoussolution. In some embodiments, combining 102 can be performed in othersolvents including diethyl ether, hexanes, dichloromethane, toluene,ethanol, methanol, ethyl acetate, acetone, and mixtures thereof Whilecombining 102 the nanoparticle, the styrene monomer, and the radicalinitiator, the styrene monomer coats a surface of the nanoparticlethrough intermolecular forces including Van der Waals forces,dipole-dipole forces, and hydrogen bonding.

In the method 100, nanoparticles may include any metal including iron,magnetic iron, non-magnetic iron, and combinations thereof. For examplenanoparticles may include any allotrope, iron (II) oxide, iron (III)oxide, and iron dioxide. The nanoparticles may have a surface area fromabout 10 square meters per gram to about 5,000 square meters per gram.Preferably, the nanoparticles may have a surface area of about 100square meters per gram, or of about 500 square meters per gram. Theinventors have discovered that a surface area of about 100 square metersper gram to about 500 square meters per gram advantageously provides ahigh number of attachment sites for lithium to promote efficientrecovery while providing a nanoparticle of a size that facilitatescapture of the nanoparticle. The radical initiator may include benzoylperoxide, di-tent-butyl peroxide, methyl radical sources, benzoyloxylradicals, methyl ethyl ketone peroxide, acetone peroxide,peroxydisulfate salts, halogen peroxides, azo compounds such asazobisisobutyronitrile (AIBN), and combinations thereof.

As shown in FIG. 1, in some embodiments, method 100 includespolymerizing 104 the monomer. Polymerizing 104 the monomer includesactivating the radical initiator to initiate the polymerization processof the styrene monomers to form polystyrene-coated nanoparticles.Activating may include heating or inducing radical formation of the freeradical initiator to instigate polymerization of the styrene monomer.Polymerization can be performed in an aqueous solution including wateror in a solvent such as diethyl ether, hexanes, dichloromethane,toluene, ethanol, methanol, ethyl acetate, acetone, and mixturesthereof. In some embodiments, at least about 75% of the surface area ofthe nanoparticles is coated with the polystyrene. The inventors havediscovered that when the coverage of the surface area of thenanoparticle is too low, the styrene monomer may fold thereby blockingsites that the crown ether may attach to. In preferred embodiments, atleast about 75%, or more preferably all, of the surface area of thenanoparticle is coated with the polystyrene. Sufficiently covering thesurface area of the nanoparticles with polystyrene advantageouslyprovides for sites for a crown ether to bind in a high yield. If thepolystyrene coverage is low, the crown ether has fewer sites to bind to,which lowers the metal-ion binding capabilities of the nanoparticles.The higher the polystyrene cover of the nanoparticles, the higher thebinding yield of the crown ether on the polystyrene, thereby creatingmore crown ether sites on the nanoparticle to bind metal ions.

The method 100, as shown in FIG. 1, includes adding 106 a crown ether tothe polystyrene-coated nanoparticles to form a metal ion adsorbingmedium such as a lithium ion adsorbing medium. The crown ether may bindto the polystyrene-coated nanoparticles so that the crown ether mayadvantageously bind to metal salts including lithium, sodium, potassium,aluminum, cesium, magnesium, and combinations thereof Crown ethers suchas dibenzo-12-crown-4-ether may bind to the polystyrene coatednanoparticles through the dibenzo portion of the crown ether, therebyleaving the crown ether portion available to bind metal salts such alithium. Crown ethers may bind to polystyrene coated nanoparticlesthrough covalent bonds, pi-stacking, Van der Waals forces, dipole-dipoleforces, and combinations thereof. In some embodiments, the crown etherincludes dibenzo-12-crown-4-ether, diaza-12-crown-4 ether,dibenzo-15-crown-5 ether, diaza-15-crown-5 ether, dibenzo-18-crown-6ether, or diaza-18-crown-6 ether. In some embodiments,dibenzo-15-crown-5 ether and diaza-15-crown-5 ether may be used to bindsodium metal ions. Methods and compositions using dibenzo-18-crown-6ether and diaza-18-crown-6 ether may be used to bind potassium metalions. Adding 106 a crown ether to the polystyrene-coated nanoparticlesmay be performed in an aqueous solution including water or in a solventsuch as diethyl ether, hexanes, dichloromethane, toluene, ethanol,methanol, ethyl acetate, acetone, and mixtures thereof.

The methods 100, as shown in FIG. 1, includes separating 108 a metal ionadsorbing medium from the solvent and building blocks used to make it.Separating 108 can be performed through filtration, centrifugation,magnetization, and combinations thereof. After separating 108, theisolated metal ion adsorbing medium can be washed with a solventincluding water to remove any unbound monomer or crown ether. In themethod 100, a brine solution may then be added 110 to the metal ionadsorbing medium so that the metal ion adsorbing medium can adsorb oneor more metal ions from the brine solution to form a metal-richadsorbing medium and a metal-depleted liquid. For example, the method100 includes exposing a lithium ion adsorbing medium to a brine solutionrich in lithium to form a lithium-rich adsorbing medium and alithium-depleted liquid.

According to some embodiments, if a magnetic nanoparticle is used, themethod 100 includes using a magnet 112 to separate a metal ion depletedsolution from the magnetic metal-rich adsorbing medium. This selectivelysequesters the desired metal ion such as lithium via the nanoparticlefrom the other metal ions that remain in the brine solution. To removethe metal ion from the metal-ion rich adsorbing medium, the metal ionadsorbing medium may be combined 114 with an acid solution to form anextracted metal ion and a recycled metal-absorbing medium. For example,a lithium ion adsorbing medium may be combined 114 with an acid solutionto form an extracted lithium ion and a recycled metal-absorbing medium.Acid solutions preferably include a weak acid such as carbonic acid,acetic acid, phosphoric acid, hydrofluoric acid, oxalic acid, andcombinations thereof. While strong acids may also be used, they maydamage the styrene coated nanoparticle thereby limiting the ability torecycle the nanoparticle.

According to some embodiments, the method 100 includes separating 116 arecycled metal-ion adsorbing medium from an extracted metal-ion.Separating includes filtration, centrifugation, magnetization, andcombinations thereof. The recycled metal-ion adsorbing medium may berecycled 120 a number of times in either iterative processes to recoverlithium from a single batch of a lithium-ion containing liquid to removemore lithium from that batch or may be used to remove lithium frommultiple lithium-ion containing liquid batches. In some embodiments, alithium-ion adsorbing medium may be used to adsorb lithium from a batchof a lithium-ion containing liquid at one site and then may betransported to another site to isolate the lithium from the lithium-richadsorbing medium formed. Additionally, all method 100 steps may beperformed at a single site.

As shown in FIG. 1, the method 100 includes precipitating 118 anextracted metal-ion to form a precipitated metal salt. For example, amethod 100 includes precipitating 118 an extracted lithium ion to form aprecipitated lithium salt, where the precipitated lithium salt includeslithium carbonate, lithium silicate, lithium oxalate, and combinationsthereof. To precipitate the metal salts, a carbonate, silicate, oroxalate source may be used. After precipitating 118, the metal salts maybe separated 122 from the aqueous solvent through a filtration orcentrifugation process. The separated aqueous solvent may be disposed124 of and the separated metal salts may be dried 126. For example,lithium salts may be dried 126 through heat, under vacuum, andcombinations thereof. Lithium salts may be dried through calcinationincluding a thermal treatment process in the absence or limited supplyof air or oxygen. In some embodiments, calcination may be advantageouswhere salt decomposition or contamination may occur.

According to some embodiments, the method may be used to make a metaladsorbing medium for recovering metal ions from a metal-ion containingliquid. For example, this disclosure relates to lithium adsorbing mediumfor recovering lithium ions from a lithium-ion containing liquid. Thelithium ion adsorbing medium includes a nanoparticle including an ion, ananoparticle coated with a polystyrene, and a crown ether attached tothe polystyrene. Iron includes magnetic iron, non-magnetic iron, iron(II) oxide, iron (III) oxide, iron dioxide, and combinations thereof.Crown ethers include dibenzo-12-crown-4-ether, diaza-12-crown-4 ether,dibenzo-15-crown-5 ether, diaza-15-crown-5 ether, dibenzo-18-crown-6ether, and diaza-18-crown-6 ether. The metal adsorbing medium mayselectively bind a desired metal ion. Selectivity may be defined asfollows:

Selectivity=((# of moles of desired metal ion)/(# of moles of undesiredmetal ion))×100%

Inorganic nanomaterials have unique physical properties. Thisapplication discusses the combination of nanoparticles, coatingprocedures, and use of crown ethers to achieve recovery of lithium fromthe liquids. Separation of lithium ions from streams of cationsincluding alkali metals of sodium and potassium is difficult. Theselective functional ring group dibenzo-12-crown-4-ether has a highselectivity for lithium. The magnetic nanoparticles are covered orcoated with polystyrene by polymerizing styrene over the surface of themagnetic nanoparticles. The polystyrene covering of the magneticnanoparticles provides for the attachment of thedibenzo-12-crown-4-ether via the benzene rings of the crown ether andthereby allows the cyclic ether to be available to adsorb the lithiumcation.

The iron nanoparticle is covered by polymerizing styrene monomer overthe nanoparticle surface followed by attaching the crown ether viaadsorption of the benzene ring of the dibenzo-12-crown-4-ether ring.

The nanoparticle is added to a solution containing a free radicalinitiator and styrene monomer. The nanoparticle maybe separated throughuse of the magnetic properties of the nanoparticles or other particleseparation techniques such as centrifugation or filtration. The styrenemonomer is then polymerized to coat the nanoparticles. The crown etheris then added as a liquid above its freezing point of 16° C. and belowits boiling point of 70° C. The material is agitated to allow the crownether to adsorb on the styrene polymer coating.

The crown ether rich magnetic nanoparticles are added to the liquidcontaining the lithium ion. This can either be as slurry or a solid. Thecrown ether coated particles preferentially adsorb the lithium from thebrine or liquid. The nanoparticles can then be removed from the liquidstream utilizing their magnetic properties or through industrialtechniques such as filtration or centrifugation.

The lithium containing nanoparticles are then extracted to put thelithium in solution. The extractants can be one of several acids orwater that has been treated with a weak acid such as carbonic acid,acetic acid, phosphoric acid, hydrofluoric acid, oxalic acid, andcombinations thereof. The dissolved lithium is then precipitated throughthe use of carbonate, silicate or oxalate, ion.

As will be understood by those skilled in the art who have the benefitof the instant disclosure, other equivalent or alternative compositionsand methods, and systems for recovery of lithium from liquid solutionswith nanoparticles can be envisioned without departing from thedescription contained herein. Accordingly, the manner of carrying outthe disclosure as shown and described is to be construed as illustrativeonly.

Persons skilled in the art may make various changes in the shape, size,number, and/or arrangement of components or method steps withoutdeparting from the scope of the instant disclosure. For example, thenumber of crown ethers may be varied. In some embodiments, crown ethersmay be interchangeable. Interchangeability may allow isolation ofdifferent types of salts. Each disclosed method and method step may beperformed in association with any other disclosed method or method stepand in any order according to some embodiments. Where the verb “may”appears, it is intended to convey an optional and/or permissivecondition, but its use is not intended to suggest any lack ofoperability unless otherwise indicated. Where open terms such as“having” or “comprising” are used, one of ordinary skill in the arthaving the benefit of the instant disclosure will appreciate that thedisclosed features or steps optionally may be combined with additionalfeatures or steps. Such option may not be exercised and, indeed, in someembodiments, disclosed systems, compositions, apparatuses, and/ormethods may exclude any other features or steps beyond those disclosedherein. Elements, compositions, devices, systems, methods, and methodsteps not recited may be included or excluded as desired or required.Persons skilled in the art may make various changes in methods ofpreparing and using a composition and a method of the disclosure.

Also, where ranges have been provided, the disclosed endpoints may betreated as exact and/or approximations as desired or demanded by theparticular embodiment. Where the endpoints are approximate, the degreeof flexibility may vary in proportion to the order of magnitude of therange. In addition, it may be desirable, in some embodiments, to mix andmatch range endpoints.

All or a portion of a method or composition for recovery of lithium fromliquid solutions with nanoparticles may be configured and arranged to bedisposable, serviceable, interchangeable, and/or replaceable. Theseequivalents and alternatives along with obvious changes andmodifications are intended to be included within the scope of thepresent disclosure. Accordingly, the foregoing disclosure is intended tobe illustrative, but not limiting, of the scope of the disclosure asillustrated by the appended claims.

The title, abstract, background, and headings are provided in compliancewith regulations and/or for the convenience of the reader. They includeno admissions as to the scope and content of prior art and nolimitations applicable to all disclosed embodiments.

1. A method for recovery of lithium ions from a lithium-ion containingliquid, the method comprising: coating a nanoparticle with a styrenemonomer; polymerizing the styrene monomer to form a polystyrene-coatednanoparticle; attaching a crown ether to the polystyrene-coatednanoparticle to form a lithium adsorbing medium; exposing the lithiumion-containing liquid to the lithium adsorbing medium to form alithium-rich adsorbing medium and a lithium-depleted liquid; andextracting the lithium ion from the lithium-rich adsorbing medium toform an extracted lithium ion and a recycled lithium-adsorbing medium.2. The method of claim 1, wherein the nanoparticle has a surface areafrom about 10 square meters per gram to about 5,000 square meters pergram.
 3. The method of claim 1, wherein the nanoparticle has a surfacearea from about 100 square meters per gram to about 500 square metersper gram.
 4. The method of claim 1, wherein the nanoparticle includes aferrous material.
 5. The method of claim 4, further comprisingmagnetically separating the lithium-rich adsorbing medium from thelithium-depleted liquid.
 6. The method of claim 1, wherein thenanoparticle includes a non-magnetic iron.
 7. The method of claim 1,wherein extracting the lithium ion from the lithium-rich adsorbingmedium includes treating the lithium-rich adsorbing medium with a weakacid.
 8. The method of claim 7, wherein the weak acid includes at leastone of carbonic acid, acetic acid, phosphoric acid, hydrofluoric acid,oxalic acid, and combinations thereof
 9. The method of claim 1, furthercomprising separating the extracted lithium ion from the recycledlithium-adsorbing medium.
 10. The method according to claim 9, furthercomprising precipitating the extracted lithium ion to form aprecipitated lithium salt, wherein the precipitated lithium saltincludes at least one of lithium carbonate, lithium silicate, lithiumoxalate, and combinations thereof.
 11. The method of claim 10, furthercomprising drying the precipitated lithium salt to form a dried lithiumsalt.
 12. The method according to claim 1, wherein the crown etherincludes at least one of dibenzo-12-crown-4-ether, diaza-12-crown-4ether, dibenzo-15-crown-5 ether, diaza-15-crown-5 ether,dibenzo-18-crown-6 ether, and diaza-18-crown-6 ether.
 13. The method ofclaim 11, wherein the crown ether includes dibenzo-12-crown-4-ether. 14.The method of claim 1, further comprising separating the lithium-richadsorbing medium from the lithium-depleted liquid by centrifugation. 15.The method of claim 1, wherein the polystrene-coated nanoparticle isstable such that exposing the polystyrene-coated nanoparticle to anacidic condition does not degrade the polystyrene-coated nanoparticle.16. The method of claim 1, wherein the extracting includes exposing thelithium-rich adsorbing medium to a water containing a carbon dioxide.17. The method of claim 1, wherein the coating includes adding thenanoparticle to a solution containing the styrene monomer.
 18. Themethod of claim 1, wherein the polymerizing includes adding a freeradical initiator to the styrene monomer, and the free radical initiatorincludes at least one of benzoyl peroxide, di-tent-butyl peroxide, amethyl radical source, a benzoyloxyl radical, methyl ethyl ketoneperoxide, acetone peroxide, a peroxydisulfate salt, halogen peroxide, anazo compound such as azobisisobutyronitrile, and combinations thereof.19. A method for manufacturing a lithium adsorbing medium, the methodcomprising: coating a nanoparticle with a styrene monomer; polymerizingthe styrene monomer to form a polystyrene-coated nanoparticle; andattaching a dibenzo-12-crown-4-ether to the polystyrene-coatednanoparticle to form the lithium adsorbing medium.
 20. A lithiumadsorbing medium for recovering lithium ions from a lithium-ioncontaining liquid, the lithium adsorbing medium comprising: ananoparticle including a ferrous material; a polystyrene coating asurface of the nanoparticle; and a crown ether attached to thepolystyrene.
 21. The lithium adsorbing medium of claim 20, wherein theferrous material includes at least one of a magnetic iron, anon-magnetic iron, and combinations thereof.
 22. The lithium adsorbingmedium of claim 20, wherein the crown ether includes at least one ofdibenzo-12-crown-4-ether, diaza-12-crown-4 ether, dibenzo-15-crown-5ether, diaza-15-crown-5 ether, dibenzo-18-crown-6 ether, anddiaza-18-crown-6 ether.
 23. The lithium adsorbing medium of claim 22,wherein the crown ether includes dibenzo-12-crown-4-ether.
 24. Thelithium adsorbing medium of claim 23, further comprising a lithium ionattached to the dibenzo-12-crown-4-ether.
 25. The lithium adsorbingmedium of claim 20, wherein greater than about 75% of a surface of thenanoparticle is coated with polystyrene.
 26. The lithium adsorbingmedium of claim 20, wherein greater than about 95% of a surface of thenanoparticle is coated with the polystyrene.
 27. A lithium adsorbingmedium for recovering lithium ions from a lithium-ion containing liquid,the lithium adsorbing medium including a polystyrene-coated nanoparticleand a crown ether, the lithium adsorbing medium prepared by a processcomprising the steps of: coating a nanoparticle with a styrene monomer;polymerizing the styrene monomer to form the polystyrene-coatednanoparticle; attaching the crown ether to the polystyrene-coatednanoparticle to form a lithium adsorbing medium; exposing the lithiumion-containing liquid to the lithium adsorbing medium to form alithium-rich adsorbing medium and a lithium-depleted liquid; and,extracting the lithium ion from the lithium-rich adsorbing medium toform an extracted lithium ion and a recycled lithium-adsorbing medium.28. The lithium adsorbing medium of claim 27, wherein the nanoparticleincludes at least one of a magnetic iron, a non-magnetic iron, andcombinations thereof.
 29. The lithium adsorbing medium of claim 27,wherein the crown ether includes at least one ofdibenzo-12-crown-4-ether, diaza-12-crown-4 ether, dibenzo-15-crown-5ether, diaza-15-crown-5 ether, dibenzo-18-crown-6 ether, anddiaza-18-crown-6 ether.
 30. The lithium adsorbing medium of claim 29,wherein the crown ether includes dibenzo-12-crown-4-ether.
 31. Thelithium adsorbing medium of claim 27, wherein greater than about 75% ofthe surface of the nanoparticle is coated with the polystyrene.
 32. Thelithium adsorbing medium of claim 27, wherein greater than about 95% ofthe surface of the nanoparticle is coated with the polystyrene.